Partial Knowledge Sucks
by slayst
Summary: Dying was awful, as was reincarnating into a fictional universe. Discovering that the plot was already a mess and now involved actual deities from an entire different lore... that was worse. 'Knowledge Comes At A Price' Omake, basically.
1. Old Soul, New Beginnings, Future Problem

Welcome, dear readers, to _"Partial Knowledge Sucks"_. In this side story to "_Knowledge Comes at the Price"_, I'll be dropping a SI / Outsider in my little crossover with knowledge of both universes but not of the setting itself.

I hope you'll have a good time reading this.

Many thanks to Kayefta and all the other beta-readers.

If you want to discuss with me and your fellow readers, or simply keep up to date with the story, feel free to join us on the Discord at /Q5aWwdR.

_"Souls don't break, they bend."_

* * *

Old Soul, New Beginnings, Future Problems

* * *

Leah Campbell was born on December 21st, 1980, in the town of Neath, Wales. She grew up with two loving parents, an adorkably annoying little brother, and a pet cat, making her officially the most normal, generic little girl this side of the English Channel.

Then, shortly before her Year 6 start of term, her parents had received a letter inviting their daughter to acquire a wand, a cauldron, numerous grimoires and school robes, among other things, in order to attend a certain prestigious learning institution in the northern parts of England on the 1st of September, 1991.

So, Leah Campbell was apparently what one would commonly call a muggleborn witch. But really, she was still the exact same little girl, with the exact same family and experiences. The only difference being that, now, Leah was the most normal, generic little witch this side of the English Channel.

Shopping done and magic train boarded, she'd reached the castle by boat at nightfall. Wonder and anxiety had mixed in her gut when a smelly, old Sorting Hat had been dropped on her head, and that's when things started to go pear-shaped. The sentient - or semi-sentient? - artefact had taken one look inside her head and immediately put her in Slytherin. That is, the House of Cunning and Ambition, so utterly prejudiced that even half-blood magicals were considered a rarity in their ranks and semi-ostracized. And, friendly reminder, Leah was a muggleborn. The first muggleborn in the last twenty-something years to be sorted in the House of the Snake, to be exact.

Leah Campbell was no longer a normal, generic little witch. Now, she was a puzzling oddity for most of the school and an absolute anomaly for the rest. A lone sheep in a vipers' nest… or was it a snake in sheep's clothing?

It was the second, unquestionably. Because as much as it pained her to admit, Leah Campbell had _never_ been a normal, generic little girl.

Leah Campbell wasn't born on December 21th, 1980, in the town of Neath, Wales. The _extraplanar soul_ that would become known as Leah Campbell was _reborn_ on December 21th, 1980, in the town of Neath, Wales. Her _second childhood_ involved growing up with two loving parents, an adorkably annoying little brother, and a pet cat. And shortly before her Year 6 start of term, her _new_ parents had received a letter inviting their _not-daughter_ to attend a learning institution she'd firmly believed to be _entirely fictional_, five years before her _birth._

Was it any surprise then, that the actually-twenty-two eleven year old girl with _three times the amount of life experience of her peers and knowledge of a possible future_ would be placed in Slytherin? That, from the moment she'd recognized the letter for what it was and accepted the impossibility that was her new existence, she'd started to make plans? That she'd vowed, from all the height of her 142cm, that she'd make the 'canon' universe _bow_, because this world deserved_ better?!_

No, it wasn't. And it didn't matter one bit what the rest of the school thought, because the Sorting Hat had been nothing but fair and sending her to Slytherin House had been the _only_ logical choice.

Except that what the rest of the school thought actually did matter quite a bit. There she was, actively trying to circumvent destiny itself - which may or may not actually be a thing in this universe - and nobody, _nobody_ had been willing to work with her until the middle of her first year. A few of her housemates had bullied her, the rest had almost universally elected to ignore her, and the other students had regarded her like a poisonous mushroom. Or, you know, a snake. At best, the witch had had cordial exchanges with Blaise Zabini, after repeatedly working with him in potions class, and something of a tentative friendship with Tracey Davis, whom she'd got to know over her first christmas break, when the brunette's best friend Daphne Greengrass had been away.

The Golden Trio, she hadn't yet had a chance to approach. She'd missed them in their first Express ride, and her being Sorted into Slytherin had nicely assured that, barring excruciating circumstances, they would remain strangers.

The troll incident would have worked nicely in that regard, and so would have Quirrell's final attempt on the Philosopher's Stone, but Leah had ultimately decided against involving herself, figuring that the whole diary, basilisk, parselmouth issue in their second year, would give her more of an excuse to approach them. More specifically, Harry. From one outcast to another, the spurned Slytherin to the repudiated Gryffindor.

After all, her own existence notwithstanding, this first year had rigorously followed the canon. Why, then, would their second year be any different.

That's when things had started to spin more and more out of control.

Harry and Ron taking the Express, instead of crashing Arthur Weasley's car into the Whomping Willow, meant that no barrier had stopped them from doing so and that something had happened with Dobby the house elf. It also meant that Ron hadn't broken his brother's wand, creating a flurry of small changes all around, including Lockhart's ironic retribution becoming seemingly unattainable. The car not being let loose in the Forbidden Forest would also make it significantly harder for the boys to escape from the nest of Hagrid's giant Acromantula, Aragog.

By that point, Leah was worried, but not overly so. Those could simply be the first butterflies, her own presence in the timeline finally affecting events. It sucked, but it wasn't anything she couldn't handle.

And then Harry had yelled at Oliver Wood, and the twice-born girl had almost _lost it!_

Out of _nowhere_, the young Gryffindor had started to act harshly, becoming distant from everyone and everything, glaring and snapping at whoever _dared_ to approach him, as if he was the second coming of Severus Snape. It was clear as day that he was struggling with _something_, and the Slytherin had feared that this something was a certain Tom Riddle's diary.

If Harry had somehow received the horcrux instead of Ginny, then her foreknowledge was basically useless. She may know how to deal with the possessed Weasley girl, but a possessed Boy-Who-Lived? A horcrux hijacking a body already containing another horcrux? What the heck was she supposed to do against _that?!_

Kill it with fire? Cry? Stop, drop and roll? Ask for her mommy? Avada herself? Swear allegiance to her fellow undead? Punch him in the throat?

And just when she was starting to _really_ lose her mind over it, the universe decided to throw another few curve balls her way.

Apparently, Cedric Diggory, fourth year Hufflepuff prefect - that sounded wrong, for some reason - not only knew, but tutored unpopular, looked-down-upon first year Ravenclaw Luna Lovegood.

What the first.

About a week later, a worried Hermione - thought admittedly not as worried as Leah - initiated a shouting match with Harry. It was promptly resolved by the two protagonists and revealed that the green-eyed boy had basically been conducting magical R&D - mostly R - on his spare time, supposedly explaining his recent behavior.

What the second.

Moving on to October 5th, the Golden Trio had been bantering with Draco in the corridor after a forgettable DADA class, when the blond had decided to unplug his brain and insulted Harry's parents. Understandably, the Gryffindor had reacted… poorly. Some sort of pressure wave had swept across the students, seized everyone by the throat and lazily zapped them with static. Then Luna of all people had jumped in, talked Harry down - because they knew each other now, for some obscure reason - and cursed Draco out of the discussion.

What the third.

Those events had soon become _the_ hot topic across all four Houses. Comparatively, the Hogwarts grapevine barely batted an eye at the Gryffindor's second wand, an heirloom that he'd supposedly retrieved from his family's vault in Gringotts. You know, not his trust found, but the main family vault _that he shouldn't have access to!_

What the fourth.

And to top off this growing pile of increasingly, _worryingly_ non-canon episodes, Halloween night 1992 had gone by without a hitch. No petrified cat, no threatening message, no _nothing_.

What the fifth.

Today was November 1st, 1992, and second year Slytherin Leah Campbell was on pins and needles, distractingly eating her breakfast in the Great Hall in the company of her fellow second year Slytherins. The witch was finishing her bowl of cereals, listening to her sort-of friend Tracey Davis instruct Daphne Greengrass, Blaise Zabini and Theodore Nott on the topic of caffeine addiction and how it could potentially cause one to dive into the dark arts, when a clear, vibrant noise resonated repeatedly around the room.

"May I have your attention, please?" requested Hogwarts' headmaster Albus Dumbledore, smiling benevolently as he stood at the staff table and hit his glass with a silver spoon.

Silence quickly fell on the hall.

"Thank you."

It happened in the blink of an eye.

Something shifted and the aging Headmaster disappeared. In his place stood someone else, someone that Leah recognized instantly, knowing full well of his achievements thanks to her particular baggage. This was Albus Dumbledore, master arcanist, archwizard at the pinnacle of his art, vanquisher of Gellert Grindelwald and bane of Voldemort.

It was simultaneously humbling and pants-shittingly terrifying.

"I usually try to avoid feeding rumors and keep this sort of speech to a minimum, but the staff and myself found it important to inform you of a new development."

His eyes swept the room, much like the shiver than crawled up the second year's spine - and basically everyone else's in the student body.

"Yesterday evening, Professor Flitwick discovered that one of his students was bullied by fellow Housemates, but the situation is now resolved and the offenders will be punished accordingly." revealed the old wizard, looking quite displeased with the House of the wise.

Wait, a bullied Ravenclaw... was he talking about Luna? How was Flitwick aware of the issue? Wasn't it supposed to last up to and beyond Harry's fifth year?

Great, another inconsistency. Exactly _how fucked_ was this timeline already?

"However, this incident revealed a more pressing and concerning issue." continued the Headmaster, ignorant of the young witch's panicked thoughts.

His wand moved and a green… _liquid_, she supposed, poured from the sky-viewing ceiling. It kinda looked like mercury, if mercury had been syrup-thick, visibly releasing ethereal vapor and could casually no-sell gravity.

"Filius, if you please."

The Charms professor nodded and took his wand to his temple, from which he seemed to reel out a wisp of silvery light.

Wait, that was a memory. So, this liquid stuff was an alternative form of pensive, but for public screenings? Kinda like the Death Chamber in Fantastic Beasts? She really hoped this one wasn't made of lethal poison.

The extracted souvenirs were flicked at the flowing surface, which immediately began to replay them from Professor Flitwick's point of view, and not a third-person perspective.

It showed the vertically challenged wizard carefully entering a dorm room and finding it already occupied. Several sleeping figures populated the beds, which was expected, and a kneeling silhouette was sneakily rifling through their school trunks, which wasn't. The half-goblin paused to gauge the unaware intruder for a second, before flicking out a spell at their unprotected back.

It never connected.

His target _moved_ and, in doing so, revealed the design of their leather armor. More importantly, the stylized bird crowing at the full moon, emblazoned on the torso.

Leah's brain short-circuited.

"Meet Azra Nightwielder," Dumbledore uselessly introduced the stranger. "Hogwarts student, thief and -"

"BUUUULLSHIIIIT!"

Her shout drew every eye on her, along with an 'I beg your pardon?' from Dumbledore and a simultaneous 'Ms. Campbell!' from a scandalized McGonagall. She ignored the two of them, the only voice she registered being that of her Head of House asking a sharp yet slightly concerned 'Is there a problem, Ms. Campbell?'

"Yeah, you can say that," she replied. "You have a Nightingale infestation."

"Excuse me?"

"Nightingale, it's this guy's rank.. or title, whatever," she waved at the memory. "Doesn't really matter, I quit."

"What?"

"Hogwarts, I quit," she repeated, as if talking to a toddler. "I can handle Riddle, and the basilisk, the dementors, even Umbridge, but I draw the line at master thief backed by a Daedric Prince. Canon's fine, an AU I could deal with, but a crossover? Yeah, no, _screw it!_ So, thanks for the year and a half of education, but this is my resignation."

She left her seat and made for the door, not caring at bit about the incredulous looks she was receiving or the hushed whispers circulating the room.

"If you'll excuse me, I need to pack my things and convince my parents to move to the States, or France, or something. God knows the MACUSA and the MAMF will be easier to deal with than our clusterfuck of a Ministry."

The great doors slammed shut with a bang, cutting her escape.

"Miss Campbell," called out Dumbledore, calmly lowering his wand. "I had the impression that you were a reasonable, well-mannered young witch, and I would appreciate it if, in the future, you could refrain from interrupting me so rudely. Please, return to your seat."

"... seriously?"

The old wizard arched an eyebrow, daring her to question his word.

"Ms Campbell, please, return to your seat." insisted her Potion professor, urgent look in his eyes.

She sighed and plopped back down next to Tracey, who was now looking at her as if she'd grown a few dozen more appendages without the help of any hex. Basically, the same look that the rest of the room was alternatively giving her and the Headmaster.

"As I was saying," coughed Dumbledore, seemingly unconcerned with the situation. "Meet Azra Nightwielder. Hogwarts student, thief and self-appointed vigilante. His true name or actual motives are unknown, as is the true extent of his abilities, though he has already displayed high agility, keen spatial awareness, some skills in non-magical lock picking and seems to have created an unheard-of spell similar to apparition unhindered by the school wards. His presence has already been signaled to the Board of Governors and the school was given the green light to reinforce security. The Department of Magical Law Enforcement was also informed and Amelia Bones graciously lent us an Auror team. They will arrive later today and will now run their own patrols, in parallel to the prefects and Professors. Now, I would typically advise you to report any information you may have to your Head of House, and avoid unnecessary conflict at all cost. But it would appear, Ms Campbell, that you already know quite a few things about this individual. Would it be terribly rude of me to ask for some clarification?"

"Yes." she volleyed back.

"I see." nodded the man. "I'm asking you for some clarification."

"That's rude." deadpanned the Slytherin.

"I'm not quite certain you understand your situation, Ms Campbell."

"And I'm quite certain you don't understand what you're asking me, Headmaster."

"This is not a _game_, young lady."

She snorted, he ignored it.

"Most of what you just said, I can't even begin to understand, but I _did_ recognize a certain name. An old name now, that not many still know, nor even dare to speak. It is highly privileged, highly dangerous knowledge, Ms Campbell. And you used it as if you were discussing the weather."

"... you ever thought about making the information more widely known?" asked the reincarnated girl, eyes passing over the entire student body. "Wouldn't hurt, in my opinion."

"Duly noted, but that is not the point. At the moment, you are still one of my students, Ms Campbell, and I am trying to determine if I am to protect you accordingly, or deliver you to the DMLE."

"Albus, surely this would be blowing things out of proportions." interjected her Head of House, frowning at the older wizard.

"I disagree, Severus. As Hogwarts' Headmaster, the students' wellbeing will always be my priority, but Ms Campbell's allegiances have now been called into question. What little information I have lead me to believe that her true designs could be harmful to her peers and contacting Law Enforcement would be the rightful thing to do." reasoned the man, before fixing back his sight on her. "Only because you remain a member of this facility, am I giving you the benefit of the doubt. Thus explaining how exactly you came across that name, and what you know of Mr Nightwielder, would be in your own interest. So please, stop acting childishly and work with me."

"I'm not being childish, Headmaster, I'm being pragmatic." countered the Slytherin, tapping a finger against the coat of arms emblazoned on her school robes. "Answering your first query would get me hospitalized and labelled as a lunatic. Answering the second would get me shanked by a Nightingale. I'm taking the safer option and answering neither."

"You believe Azra to be ill-intentioned, then?" frowned the wizard, skillfully ignoring the initial part of her statement.

"Nightingales are true neutral, chaotic neutral at worst. Thieves, not killers, unless they're dealing with a rogue element." she denied. "But our friend is still a career criminal working for a chaos goddess. If I start babbling secrets, you can be damn sure that he'll react, and I _don't_ fancy a shadow blade in the throat. So, again, not talking."

"You are of course aware, that if you persist in your silence, you are essentially forcing me to hand you over to the DMLE, and 'our clusterfuck of a Ministry'? And that, once taken in for questioning and being a muggleborn, you will be administered veritaserum and _made_ to answer?"

No. Well, yes, but not really. She knew that 'truth serum' was the go-to solution in fix-it stories and she knew that muggleborns rarely had a legal defense against it, but she certainly hadn't thought about what it meant for _her_.

She'd been too busy mentally - and vocally - snapping at seeing her hopes and dreams shatter into a million pieces. Or, you know, her plans and sanity.

Great, just… great.

She either let the cat out of the bag here and now, or it would be forcibly dragged out at the Ministry - which, even so early in the books, was _spectacularly_ corrupt.

So _that's_ how it felt to dig your own grave.

"Albus, may I remind you that I have Veritaserum in my stocks?" suddenly offered her Head of House. "Involving the DMLE isn't necessary."

Alright, that was marginally better. Same promise, thought. Talk, or we'll make you. Was Snape defending her, or going along with the Headmaster on that one? Either way, she was stuck. Willing or not, the truth was coming out.

Welp, canon was fucked anyway, might as well break it on her terms.

"... I have conditions."

Albus Dumbledore smiled.

"Let's hear them then."


	2. World Serpent

Welcome back, dear readers, to _"Partial Knowledge Sucks"_.

**_Chapter 1 was almost entirely reworked, so get back to it or you'll be completely lost._**

Many thanks to DALucifer, Kayefta, MysticNinj, Ryan1016, and all the other beta-readers.

If you want to discuss with me and your fellow readers, or simply keep up to date with the story, feel free to join us on the Discord at /Q5aWwdR.

_"Reality is brutal."_

* * *

World Serpent

* * *

Severus Snape was content, which certainly wasn't an everyday occurrence.

It was November 1st, 1992, and the entire population of Hogwarts, student body and staff alike, had been gathered in the Great Hall. Firstly, for breakfast, as was customary, but secondly, to reveal the existence of an elusive figure, going by the ridiculous name of Azra Nightwielder - with such poor naming sense, it had to be a Gryffindor - that Filius had caught sneaking around Ravenclaw tower.

This mysterious individual was apparently intent on righting wrongs around the school by acting like a common thief, making him a sort of discount Robin Hood wannabe. A most ridiculous idea, but one that had already borne fruit. His unknown objectives, morals, abilities and lineage had sent the Board of Governors into a full blown panic and made them authorize Albus to tighten up security. Similarly, the DMLE was informed and a team of Aurors was to be dispatched to the school later that day.

But clearly, none of that was responsible for Severus' current mood.

The source of his satisfaction was in fact one of his charges, second year Slytherin Leah Campbell, the infamous muggleborn snake.

When she'd joined his House last year, he'd been… disappointed, was a good word. Not at the girl, but at what she'd been condemned to. The Dark Lord's persistent efforts all those years ago had sent Slytherin House drifting further and further away from its true values, turning it into a cesspool of vanity, bigotry and resentment. Very few of his students nowadays were truly cunning or properly ambitious, and the young witch had to be both, or the Hat would have never sent her their way.

But with the House in its current state, she would never be able to express those traits. Her housemates would either ignore, belittle, or downright bully her because of her lineage. The other students would equally judge her, simply for wearing green and silver, and she would be pushed aside. Condemned to be alone, truly alone, for the remainder of her school years. And the Slytherin within would forevermore stay under the surface, losing any chance of shedding out of its skin.

At least, that had been true up until now.

Because at this exact moment, Leah Campbell was playing a verbal tennis match with the Headmaster. And sure, he'd tried to help her twice and she was still losing, but the girl was facing Albus Dumbledore, so it was acceptable. She was actually holding her ground quite admirably, letting her buried Slytherin self shine through.

It was for rare moments like these that Severus endured his job.

Although, he could have done without the thief, or Ms Campbell impossibly knowing things that she had no business knowing.

Albus had just finished explaining how keeping silent wouldn't help her any once the DMLE put their hands on her, and the Potion Master could see in her eyes that the twelve year old had been backed into a corner. Her secrets would come out, whether she liked it or not. Here, or at the hands of Law Enforcement.

But she was one of his, and if he couldn't prevent this situation, he could at least present her with an alternative. The Ministry certainly didn't look any more appealing to him than it did to her.

"Albus, may I remind you that I have Veritaserum in my stocks?" he interjected, hoping Ms Campbell would recognize his intervention for what it was. "Involving the DMLE isn't necessary."

His employer sent him an unimpressed look, clearly seeing through his maneuver. The young witch's eyes, in comparison, looked more calculating.

"... I have conditions." she finally relented.

Seriously, she was _still_ trying to negotiate?! The rest of their House had better be paying attention.

"Let's hear them then." acquiesced Albus Dumbledore, smiling.

"First, let me be perfectly clear; _I don't want to die._ But if Nocturnal wants me dead, _nobody_ in this room will be able to stop her, or her Nightingale. I'm quite literally putting my life in your hands with this, Headmaster, so if I tell you to back off from a sensitive topic, don't be stupid and _back off._"

Nocturnal. Ms Campbell had never used that name before, but if the thief, the Nightingale was hers, then it had to be the chaos goddess mentioned earlier. Maybe a spirit of sorts? An elemental? Probably something of that sort.

"Now, before I say anything, I'm gonna need two things." continued the girl, clearly not taking no for an answer on those. "Wait, no, three. First off, you said that Amelia Bones was lending you Aurors, so I assume she's the current Head of DMLE? If so, you need to send Fawkes to retrieve her. Otherwise, have him retrieve her and whoever holds the position."

What the _heck_ was she doing? She'd spent fifteen minutes trying to avoid the DMLE, and not she asked for the Department Head?!

"Madame Bones does, in fact, lead the DMLE. May I know why I would be unceremoniously removing her from her post?"

"To serve as an impartial, non-corrupt Ministry official, give legal advice when it's needed and act on some of the things we'll be discussing."

So, she'd been trying to avoid corruption? Not Law Enforcement, but the Ministry as a whole. It certainly made sense, but how was a twelve-year old muggleborn even aware of the current state of the Ministry?

"Regarding the second thing, I'm going to need two teachers to run a quick errand in the castle. Professor McGonagall, for her Transfiguration expertise, and another."

Minerva threw a glance at Albus, received a nod and asked 'What is it you'd have me do, Ms. Campbell?'

"One sec." the girl stopped her, addressing him instead. "Professor, could you put up a _muffliato_ around Professor McGonagall?"

The Head of House inhaled sharply.

"How…?"

did she know? How did she know the incantation to a custom spell he'd designed over a decade ago, in the margins of his old _Advanced Potion-Making textbook_? A textbook now locked away in his classroom's potion closet, and that no second year should have been able to procure.

"Not important right now. The spell, please?"

He frowned, less pleased at _this_ piece of Slytherin attitude, but complied nonetheless. His wand moved and the anti-eavesdropping charm settled down around his colleague.

His student thanked him, dropping into a slight bow before going straight to the Deputy-Headmistress. A moment of muted conversation and she moved away, repeating her bow toward the woman before retreating to her seat.

Severus cancelled his spell.

"Minerva? Is something wrong?"

"I… I cannot say, Albus." admitted the Head of Gryffindor, looking quite concerned indeed. "But if Ms Campbell is right, then I certainly have an errand to run."

"I'll trust your judgment on this." acknowledged the Headmaster. "Ms Campbell, do you have a preference for the second teacher?"

"I could -" started Gilderoy Lockhart.

"Not happening." the Slytherin instantly shut him down. "Send Professor Flitwick or Professor Snape, either work."

The two of them shared a look and silently reviewed their options. Reaching a consensus, Filius rose from his seat as Severus announced 'I shall remain with my students.'

'Including Ms Campbell.' went unsaid.

"Very well." nodded Albus, turning back to the girl. "And your third demand?"

"That no questions be asked or measures taken for what I'm about to solemnly swear."

About to what?

Turning around in her seat, the young witch looked at the Gryffindor table and loudly called out two students.

"Messrs Fred and George Weasley, I have some mischief to manage and I'm going to need that thing. Do you have it on you or is it in your dorms?"

Of course she had to bring those two in on whatever she was planning. And judging by their expressions, they seemed to understand what she was talking about. Severus assuredly didn't, but he knew he wouldn't like it one bit.

"Hey, you can't just-" started to protest one of the twins.

"You want me to spill secrets, get ready to have your secrets spilled." she cut off the angry teenager. "Where is it?"

"... not cool, Campbell." complained the other redhead. "It's in the dorm."

"Professors, take them with you, they have something that should help you."

"A busy morning for everyone, unquestionably." calmly observed Albus. "Minerva, Filius, Messrs Weasley, perform your assigned tasks and return at once. In the meantime, I will write Madame Bones a note and send Fawkes to her. And Ms Campbell, I sincerely hope for you that you have acceptable answers after this whole charade."

"I have answers." shrugged "Whether or not you'll accept them is out of my hands."

"... we shall see."

* * *

If she had to truly summarize the present situation, Amelia Bones would have to settle for 'What?'.

She'd been at work, leafing through team reports, when Albus Dumbledore's phoenix had erupted in the middle of her office with a note on its leg. It was short and basically amounted to 'we need you at Hogwarts yesterday'. It didn't speak of any danger, but remained urgent in its wording, so it had to be pretty important. Probably something to do with this thief they'd reported, then. The witch had taken a minute to warn her department that she would be out and momentarily unavailable, before allowing the fiery bird to take her away.

Flaming back to reality in the school's Great Hall, she'd found herself amongst the entire population of the castle, staff and students. The Headmaster had welcomed her and introduced her to one specific second year Slytherin girl - Leah Campbell, who'd apparently requested her presence for something - before directing her to an empty seat at the head table. They were to be waiting for the return of Minerva McGonagall, Filius Flitwick and two of Arthur Weasley's children, that were conducting some kind of job and should arrive shortly, so the Department Head had had enough time to ask a few questions of the neighboring professors.

Hence, 'what?'.

Because from what they were telling her, that girl she'd just met apparently 'knew things'. Things she shouldn't know, according to the Headmaster.

And? That was it? She'd seriously been called for something as simple as a _seer_? She had _three_ of those working in the secretarial service alone. Was Dumbledore going senile or something?

The great doors were pushed open and the four stray magicals entered the room, all looking quite grave. The Professors, unknown parcel covered by a sheet levitating at their side, reclaimed their seats with a somewhat eager nod of greeting in her direction. The twin Gryffindors similarly seemed quite satisfied as they made for the Slytherin table and gave a piece of parchment to the witch that this entire thing seemed to revolve around.

"I trust that you were successful, Minerva, Filius?" asked the Headmaster, eyes shifting between his colleagues and the mysterious package they'd returned with.

"We were." confirmed the Transfiguration Professor, eyeing the covered box with distaste. "Ms Campbell was correct, but I believe I should let her explain."

All eyes fell on the young witch and she sighed softly.

"Alright, but quick disclaimer. I know things, that must have been pretty clear. But I'm not a seer. I'm not omniscient. The only thing I have is second hand information and already, some of it has been rendered moot. I'm not going to tell you the future, so much as a future. Don't be surprised if some things are off." she began. "And please, try to keep the existential crisis to a minimum."

The hall as a whole universally agreed that this was a pretty weird disclaimer.

She knew the future, or a possible future, but wasn't a seer? How did one get second hand information? Did she know someone with the gift? Had she overheard a vision? And why would they be having an existential crisis? Visions and prophecies weren't common, but they certainly weren't _rare_.

"Can someone conjure up a blackboard, please? And chalk? I'm going to need visual aid. Also, it'd be better if the staff and Madame Bones could relocate to the House tables."

They proceeded to do just that, a flick of McGonagall's wand simultaneously conjuring the requested items.

"Thank you, Professor." smiled the Slytherin, already sketching on the board. "Now, I could do this is a number of ways, but I'm the 'go big or go home' sort of gal, so I apologize in advance for the shock. The multiverse is real, this isn't my first life, the wizarding world was a work of fiction in that one, so was the universe where our Nightingale friend is coming from and the two are not supposed to interact. Digest that while I'm working."

You could have heard a pin drop.

Apart from the knocks and scratches her piece of chalk was creating, the room was dead silent, mostly out of shock or disbelief. Had this girl seriously said what they thought she'd said? No, they had to have misheard her somehow, because it was… impossible, just plain impossible.

'And exactly the sort of knowledge that would warrant an existential crisis.' whispered a small, treacherous part of her brain. 'Think about it.'

But…the multiverse… another life? Their world as… a work of _fiction_?

… wouldn't… wouldn't that mean…?

"Before anyone starts freaking out -" casually called out Campbell, still focused on the board. "- it doesn't make anything any less real. It's just multiverse theory, taken to the extreme. Anything that can happen, no matter how ridiculous or unlikely, ultimately has a one-hundred percent chance of happening in the context of an endless multiverse. Meaning that every work of fiction, every story that has, is, or will ever be written, is sure to be real somewhere, somewhen. You could imagine a completely nonsensical dialogue between a german soldier from World War One, an aztec priest and a sentient, talking piece of bacon turning into a werelocomotive on New Moon nights, and it'd still be factual in some corner of existence. Already is, actually, since I just mentioned it. Bleeding effect or something, authors are just catching glimpses across infinity. Well, that or reality's just _that_ random."

Abruptly, her hand stilled in midair.

"... glimpses." she whispered, before adopting a tone oscillating between jovial and absolutely pissed. "Aaaand I just remembered the alternate pensieve in the ceiling… great job Leah, you're a fecking _moron!_ Bloody hell, where's this _stupid thing_ even coming from?! It's canon-adjacent _at best!_ It shouldn't be a thing, it shouldn't be in the freaking Great Hall, and… ahum. Anyway, I'm almost done and you're all patiently listening to me monologuing, so just let me finish this real quick… and no comments on the moron part if you don't want to get hexed, thanks."

The chalk noises started again, a bit more frantric, and the hall slowly came back to life, hushed whispers drifting from most mouths.

Amelia remained silent, focusing on the board. It had been separated in three parts, respectively labelled NM-Earth, WW-Earth and Nirn. The first one had the labels '1st life', 'non-magical', 'HP books/films' and 'TES games' attached, along with the dates 1996-2019. Listed under WW-Earth were the words 'Fantastic Beasts', 'Harry Potter' and seven incomplete sentences like 'and the Philosopher's Stone' or 'and the Goblet of Fire', this time with dates ranging from 1991 to 1998. As for Nirn, the board shown the crude drawing of a snake, with a zoom on one scale further splitted into three parts labeled 'Aetherius - Aedra', 'Oblivion - Daedra' and 'Mundus - mortals'. Following the established pattern, the '2E583 - Online', '3E427 - Morrowind', '3E433 - Oblivion' and '4E201 - Skyrim' that were being added must have been dates, but certainly not any she recognized.

"Done." smiled the Slytherin, dusting her hands. "So, memories. Do I need to learn the spell or can someone else do the extraction?"

"I can do it for you, Ms Campbell." assured Dumbledore, approaching the student. "Just focus on what you want to show us."

She nodded and closed her eyes, letting his wand brush her temple. A frown passed her face when a slip of silver was drawn out of her head, she probably hadn't expected the pain. The Headmaster didn't comment on it and flicked the memory strand at the ceiling, the same viewing device installed in the Ministry's courts dropping down and playing the girl's supposed proof.

Hands turning the pages of a book titled 'Harry Potter and the Philosopher's Stone'. A bookshelf, with seven tomes bearing the name of that same wizard, followed by each of the incomplete sentences on the board. A television showing his Sorting from multiple perspectives, although the room seemed ridiculously small, as did the number of students. Muggles, some wearing the occasional Hogwarts robe or scarf, animatedly waiting before a cinema for the projection of 'Fantastic Beasts And Where To Find Them'. People posing and false-dueling on a stage, dressed up as witches and wizards, some of their models standing in this very room. Countless drawings of the school, creatures, and individuals. Photos, even, some showing known magicals in muggle and wizarding clothing, with the occasional message from either persona.

Most of the hall choked on air.

Alright, so those certainly counted as proof, but it still didn't explain why she'd been brought into this mess.

"Ms Campbell?" the Head of DMLE authoritatively called out over the noise brewing up by the second. "What _exactly_ am I doing here, aside from losing my mind at what you're telling us?"

"Oh, right." said the _certified dimensional traveler_, passing behind the board to retrieve the package left to wait on the main table, delivering it to her. "There you go, one Death Eater animagus to question under veritaserum. You're welcome."

"Excuse me?!" Amelia exclaimed herself, echoed by a good part of the room.

"Professors Flitwick and McGonagall acted on future knowledge and apprehended him. I assume, after checking his identity with this nifty little thing here." explained the girl, showing her the piece of parchment she'd been given earlier, putting her wand to it. "I solemnly swear that I am up to no good. Now, as you can see, this is a map of the castle. It's real nice, because it shows people in real time, with their names labeled on top. Obviously, it's unreadable right now, with so many of us in one place, but if you'd looked at it an hour ago, you would have found a name that would have had no business being on it. This person is supposed to be dead, you see. Except that the map never lies. Mischief managed. Professor McGonagall, care to share with the class?"

The addressed Transfiguration Mistress growled a low, threatening 'Peter Pettigrew!'

"What?! But…how?!"

"As I said, Death Eater animagus." repeated the Slytherin, as if that was the most sensible thing in the world. "Sirius Black stupidly convinced the Potters to switch the Fidelius over to their good friend Peter, and the man ran up straight to Voldy. He then committed all the things typically blamed on Black, framed him, and escaped through the sewers as a rat. At least, that's what happened in the story I'm familiar with. Things could be different, so I'd advise you to check with Veritaserum and not just chuck him into Azkaban, like Crouch probably did with Black."

'This… this is a mess.' mused the Bones Matriarch, eyes fixated on the innocent-looking box she was holding. They'd barely even started with the girl's unnatural knowledge and already, this sort of thing was happening. It made her fear what was to come.

"Anyway, the rat's stunned and, I assume, secured efficiently, so now that we've got that particular ball rolling, let's get back to the main event." smiled the twice-born witch, returning to the conjured board. "On the left, you have my old universe, objectively the most boring of the three but arguably the safest too. Middle's this one, that we called Potter-verse. Yes, Harry's the main character, but please don't harass the guy, he never asked for this. Then right panel is the Elder Scrolls universe, named for lore reasons, which I'm not going to go into because it's an absolute mess."

The discussions had ceased, everyone was paying attention. Which wasn't all that surprising, considering that the girl was basically displaying the secrets of the universe. Three universes, if you wanted to be technical.

"In my old world, I was born January 24th, 1996, in Lyon, France, and died at the venerable age of twenty-three. Ce dont j'pourrais sûrement vous convaincre en changeant de langue et en vous recrachant des évènements majeurs, sauf que vous auriez aucun moyen d'vérifier quoi que ce soit, que la plupart d'entre vous ne biteront pas un broc de c'que j'pourrais bien raconter de toute façon, et que tout le monde s'en_ tape_. Donc je vais m'calmer et retomber sur notre langue maternelle commune _right now_."

The_ time traveler from the future_ was grinning widely by this point, earning herself a soft snort from Flitwick and scattered laughs from the few students who apparently did speak french. Amelia herself was far from fluent, but had gotten the gist of it, despite not recognizing a few words.

Frankly, she was more worried about the girl casually admitting her own death and dismissing it in the same breath. Even if she'd had twelve years to come to terms with it, it didn't seem healthy.

"No magic for old me." carried on the Campbell girl, pointing at the list she'd made under NM-Earth. "The world simply didn't have any, as far as I'm aware and because people love escapism, the Harry Potter series became an international phenomenon. The first book came out when I was around one and the story concluded ten years later, with the seventh book. It was also made into eight films, from 2001 to 2011, plus two more movies on Newt Scamander in 2016 and 2018. Meanwhile, the Elder Scrolls universe was mainly portrayed in a series of role-playing video games. Starting with Arena and Daggerfall, that I never played, then Morrowind, Oblivion, Skyrim and Online, that I _did_ play. There's also a handful of smaller titles that weren't all that interesting, mostly because the graphics sucked, the gameplay sucked, the plot sucked, or all of those at once. The setting is classic heroic-fantasy, with continent-spanning empires, medieval weaponry, magic, sentient races by the dozen, dragons, gods, demons, alternate planes of existence and the occasional time-traveling robot from the future blowing up elves with a blaster, the works."

The witch then grabbed the discarded piece of chalk and draw a vertical line in front of every half-title in the WW-Earth section.

"_Those_ are the titles of every book in the Harry Potter canon. For the illiterates who don't know what canon means, it's the official version of the story. The films further split the last book in two and changed or ignored a number of plot points, but are usually accepted as another canon. Then you have Pottermore, a website where the author expended on the lore, which is canon-debatable but don't get me started on this or we'll be here for hours. And because the series was a planetary success, you also had inspired fans the world over that would write their own stories, ranging from fluff to grimdark and everything in between. And the shipping… so much shipping. Trust me, you don't want to know. This mess would make perfect fanfiction material, by the way. Reincarnated with metaknowledge in the canon, that turns out to be an Alternate Universe, that's actually a crossover with another franchise. Just need to avoid the overused tropes like _Lord-of-Everything_, _Inheritance Laws_ or _MOD!Harry_ and it has some serious potential for shenanigans. Anyway, back to the books. They're written from our resident Gryffindor's point of view, bar a few exceptions. Sidenote, I'm terribly sorry about the invasion of privacy, Potter, but I've seen what's in your head and you're a sassy little shit. Your father would be proud. Anyway, the books cover all of his Hogwarts years, one year at at time, so we're currently in 'Chamber of Secrets'. Yes, that's Salazar Slytherin's Chamber. Yes, it's real. Yes, I know where it is. And no, I'm not telling you."

People began to shout, mostly said Founder's House and Ravenclaws.

"Thousand year old slumbering basilisk." calmly added the technically-a-woman girl. "You're sure you want to go?"

"A BASILISK?!"

Amelia had shouted that, but so had almost all of the staff and older students. The younger crowd mostly looked confused.

"A sleeping one that's not going to wake up by itself. One of Voldy's old failsafes canonically does it and I was planning on preventing it, but since we're _apparently_ in a crossover, I'm not even sure if it's still a danger. The failsafe, I mean." explained the second year, annoyance clear in her voice. "For all I know, our Nightingale resident already found the thing and chucked it into Oblivion. And if he hasn't yet, then we'd all _greatly appreciate it if he could, thank you!_ A deadly serpent is bad for business Azra, _think about it!_"

"I believe he agrees." commented Dumbledore, pointing over her head.

The Slytherin girl turned around and spotted the bird perched on top of the blackboard. It appeared to be made of absolute emptiness and had just popped out from under the head table.

"Oooh, Shadow conjuration, nice."

It flapped its wings and seemed to tweet, but no sound was produced.

"Are you alive? Or just Azra's puppet? Pick at the board for the first, have it flap its wings for the second."

The wings went up again and just like that, the dialogue was opened.

"Great. You know, I'm surprised you didn't interfere faster. Trying to figure out if I was a threat? Same pattern, board for yes, wings for no. Alright, you were. Made up your mind yet? No? It depends on what I say? Welp, best I can ask for, I guess. So, about that failsafe and the basilisk, did you know about them? And, are they still an issue? Now _that's_ good news. The book was part of a set, do you know where the others are? If I tell you, can you handle them? Yes and no? Yes _but_ no? Sort of? Alright, sort of. You can't handle them, but Nocturnal can? Yeah, thought so. Can you see through this bird? Great, give me a minute, I'll make you a list."

The impossible girl dived behind the board to write on the opposite side, the bird joining her out of sight. Neither seemed to mind that her semi-monologue and reactions to the not-responses she'd been getting back had left their entire audience superbly dumbstruck.

So, the millenia-old basilisk had been taken care of, as had Voldemort's old failsafe - apparently a book - but he had _more_ of those? And this Nocturnal entity could just… deal with them? As if those things hadn't been created by the most powerful dark wizard of their generation?_ How?!_ And what exactly were those failsafes, anyway? How many were there, for Campbell to describe it as _a set_, instead of just giving a number?

"This one's the easiest, just get in and take it out. There's no defense whatsoever, the fucker thought it was too well hidden. This one was moved there years ago and the house may or may not be under Fidelius. Also, it _will_ require parseltongue to open and assault you with hallucinations, so watch out for that. The parseltongue wouldn't hurt for this one either, because there's some nasty defenses on the place. Once you get past that, the ring will compel you to put it on and rot your flesh if you do, cause Tom's fucking vindictive like that. We're only in 2nd year, so this one shouldn't exist yet, but crossover, so don't quote me on that. This one's _technically_ the hardest to reach, but it shouldn't be too much trouble for a Nightingale. Except that everything around it duplicates on contact and is spelled to charcoalize you, so that's fun. And this one… yeah, that's the tricky one. Nirnian Conjuration could work, maybe. Or just have Nocturnal extract it, if she can do so safely. There's always the canon solution, but I'm not sure if it'll work here, what's with the crossover. Anyway, you got all that? Can I erase?"

The construct must have given its consent, because it hoped back on the board and the sound of a hand wiping off chalk made itself heard, before the dimensional visitor returned to their side.

"Good news everyone, canon's fucked six ways to Sunday." she enthusiastically told them. "We're skipping six years of Voldy being a little shit and going straight to the dark idiot biting the dust, sparing hundreds of lives. All thanks to our friendly neighborhood Nightingale and Lady Nocturnal."

The girl gestured at the shadowy bird and it crowed silently, his summoner clearly appreciating the praise. The hall wasn't certain how to react at the news that Voldemort, that they'd all believe to be a thing of the past, wouldn't actually stay alive for much longer.

"By the way, Azra, two questions. One, why the name? The guy's a dimension-hopping shadow-archmage, he could totally drop by and kick your ass for impersonating him. You thought about that? And two, I've been mentioning your patron for the last hour or so and I'm probably confusing a lot of people. Can I introduce her properly? Titles and spheres? Quick description of a Daedric Prince, too?"

This Nocturnal entity had titles? And spheres apparently, whatever those were? And a Daedric Prince? Yes, an actual explanation would be most welcome, thank you.

The bird gave her permission with a pick at its perch and the girl turned to them with a bittersweet smile.

"Alright, I'm going to be blunt again because there's no easy way to say this. Hogwarts is now housing a deity."

… what?

"_Really_ succinctly, Nocturnal is a daedra, more specifically the Daedric Prince of the Night, Darkness and Shadows. She's also known as Lady Luck or Ur-Dra, the first of her kind, although that specific title could theoretically apply to a number of others and there's a theory that she somehow _stole_ the primogeniture, so… Anyway, daedra - its invariable - are shapeshifting, genderless beings of chaos. And I mean primordial, disorganized chaos, not kill everyone and destroy everything chaos, although some do appreciate the activity. They're also pseudo-immortal, more specifically perpetual. You _can_ kill them, but they won't _stay_ dead. Now, Daedric Princes, they go one step further and are essentially near-unkillable, near-omnipotent deities. Each Prince reigns over a number of spheres - their divine traits, or domains of influence, if you will - plus their own private dimensions, which are actually manifested extensions of their very being. They're also entirely unconcerned with the linear flow of time - in their home universe anyway, not sure about here - and exist so far above mortals that they're essentially unfathomable. Their true motives are unknown and none of them have anything even resembling a moral compass, although Nocturnal is usually regarded as neutral, as opposed to some of the _other_ Princes who can range from mostly good to exceedingly evil. So… that's good? Silver lining, right?"

Right, silver lining.

_No!_

Neutral or not, their dimension - and her home country - catching the attention of an _immortal, chaotic, all-powerful god of darkness_ couldn't possibly be qualified as good in any fashion or sense of the word.

Seriously, why in Merlin's name had Campbell asked for her specifically, instead of reaching out to the Unspeakables? Weird shit was their domain of expertise. Olson should be dealing with this!

"Shouldn't really change anything for most of us, anyway. At worst the DMLE will have to deal with an organized Thieves Guild coming out of the woodworks, and maybe another Nightingale or two. Sorry in advance, Madame Bones."

… she was going to strangle that kid, and it wouldn't even count as assault on a minor because _time travelling dimension hopper!_


End file.
